You have adopted a child abroad and would like to know the administrative procedures for entering this event in the Swiss civil status register (Infostar).
Adoptions abroad are normally recognised in Switzerland when pronounced in the country of residence or citizenship of the adopter or adopting spouses (Federal Act on Private International Law (PIL SR 291)).
A great many countries have signed the Hague Convention of 29 May 1993 on Protection of Children and Cooperation in Respect of Intercountry Adoption (SR 0.211.221.311). This Convention rules the cooperation between the relevant authorities of the country of origin of the child and of the receiving State.
You will find some very useful information on the subject of international adoption on the webpage of the Federal Office of Justice.